Each country has a different standard for its electrical plugs, thus there are different standard for its sockets that match the plugs. Generally, when a customer buys a electrical plug, it usually adapts to one country only. This may cause a lot of inconvenience. For example, for those international businessmen who often need to work in different countries, if the plugs of the laptops they are carrying may adapt to one country only, their work will be dramatically impacted.